US President Barack Obama at the Benjamin Banneker Academy High School in Washington on October 17. (GETTY IMAGES)

Washington: US President Barack Obama on Tuesday scolded Donald Trump over his repeated claims that the upcoming November 8 election was "rigged" against him, telling the Republican presidential candidate to "stop whining”.

At a joint news conference in the White House Rose Garden following meetings with Italian Prime Minister Matteo Renzi, Obama was asked about Trump's claims that US cities are rife with voter fraud and that there were efforts to "rig the election at the polling place”.

"I'd invite Mr. Trump to stop whining and go try to make his case to get votes," Obama advised.

For many months, Trump has raised the possibility of illegal activities that could tarnish the November election result, and he has urged his supporters to show up at polling locations on Election Day.

In recent days, Trump's rhetoric at campaign appearances and on social media about a rigged election has intensified as his standing in public opinion polls has fallen.

Referring to Trump's contention, Obama said: "It's unprecedented. It happens to be based on no facts."